1. Technical Field
The present invention relates generally to backing up a system, and in particular, to a computer implemented method for backing up differences from a prior system image.
2. Description of Related Art
Enterprises and individuals often backup their locally stored computer data in a remote location. On primary reason for such data redundancy is to restore the locally stored data after a data loss event such as a hard disk crash. Another purpose is to periodically retain copies of data for possible future use according to data retention policies. These data retention policies may be established and implemented for various business and legal data archival purposes including disaster recovery, statutory and judicial legal requirements, historical analysis, etc. The data being backed up may include general data, data formats, permissions, system configurations, etc.
An effective method of backing up locally stored computer data is to store a complete image of the computer system to a remote location. This would allow for easy reconstruction of the computer system in case of a partial or complete loss of computer data. One simple technique is to repeatedly store a complete image of the computer system to a remote location. This may be performed periodically, upon certain events such as when the computer system is to be shut down, or upon user request.
Another effective method of backing up locally stored computer data is to initially store a complete image of the computer system to a remote location, followed by storing incremental copies based on changes since the last update. Various techniques may be used to determine which portions of the computer system data has been modified since a previous backup. As a result of this approach, the amount of time required to perform each incremental backup is reduced, although reconstructing a complete image of the computer system may require going through the initial backup and multiple incremental backups.